Yeah, this has probably been discussed before, I'd imagine about a thousand times or so because it sounds like such a basic idea that would actually work, but it begs the question: WHY IS THERE NO FURNITURE IN MINECRAFT?
Why do I have to install a mod to put basic furniture in my house? Just add some chairs and tables so we can finally cut out the middle-man. It's like a joke that they haven't added chairs to minecraft, kind of like how they say they removed Herobrine on every update.
Designs for furniture don't have to be complicated, maybe you can add upholstery with wool or something, but it would be nice to have something to sit on while I step away from the game to go do something, or when I have visitors on multiplayer. Also, maybe adding plates to put food on?
It's just an idea. I know this doesn't sound like some big exciting feature, but it definitely would be a nice and welcome addition. Cauldrons are 90% useless but I don't mind having one in my house just because it looks nice. Same goes for flowerpots.